Separation of Serotonin from Catechols by Capillary Zone Electrophoresis with Electrochemical Detection

Capillary zone electrophoresis with electrochemical detection is demonstrated with columns having only 9-μm inner diameter. Amperometrlc detection limits of 0.7 amol are reported for serotonin. The difficult problem of resolving serotonin and dopamine—two neurotransmitters of interest having similar electrophoretic mobilities—is addressed by chemical means to Improve selectivity. These include buffer modification with 2-propanol and a system employing borate complexation of the catechol in combination with sodium dodecyl sulfate micelles.